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[Farm boy]

I am looking at Wood's TW-6hg in my '03 serk. I saw the specs on the se-253 that is in the bike. It shows .530" lift.
My question is, if I have the TW6-hg ground to .550" instead of the .590" would it work properly?
Already have heavy breather air inlet, 62psi fuel pressure regulator. Going with rinehart 4" true duals, and tts master-tune. Can go with better valve springs, if needed.
Low / mid-range torque is what I am looking for on this. Down the road, going with forged 10.5:1 wiseco pistons.

[Para Bellum]

Since you want low- and mid-range torque, you should look for a 2-into-1 (or at least a 2-into-1-into 2) exhaust system...true duals don't allow low/mid torque. True duals (2-2) require you to keep the engine in the upper RPM range, which doesn't work well with a heavier bike like the SERK.

[grc]

If you only want .550" lift instead of .590" lift, why not look at cams designed with .550" lift?  I'm not quite understanding what you're trying to do here.

Jerry

[HD Street Performance]

Ok
Buy the cam and install it with the added compression. By the way the dome is designed for bathtub heads so you will now have a mid 9 for compression with the cvo hemi head and that cam will be a little sluggish down low.
The heads work at .590, take your eyes off that and on the real issues. Arias has a proper 10.5 piston for that hemi head.
A proper 2 into 1 pipe will help your cause.

[Farm boy]

Thanks for the info. Reason for the .550, instead of .590 didn't think heads would take the .590. Can't do head work right now, but wanted to work towards it. Have built diesel (Caterpillars), pontiacs, and chevys, so the wrenching isn't a problem.  Porting and polishing,  not so much.
I really like the way the true duals sound,  but would like some better low end than what I have now. Willing to give up some to keep the true duals.
Was looking at dyno charts for the TW-6hg and it looked like it was producing good flat torque from about 2500 rpm.
Open to suggestions, but looking for gear drive cams.
P.S. reread and saw that heads will work at .590 lift???
Didn't think the '03 heads would take that much lift.

[Para Bellum]

Low / mid-range torque is what I am looking for on this.

would like some better low end than what I have now. Willing to give up some to keep the true duals.

Twice you said you wanted better low end, then said you're OK with loss of low end.  Have you decided which you want?

[HD Street Performance]

The cvo 103 has 8.5 or less compression.
That culls torque
The wonky cam HD used ditto.
The true duals last but not least hit.
Get it to a true 10.5:1 fluid verified and deck height factored in and use that cam. It will hit pretty hard and let you know you have solids, or at least it will sound that way.

[Farm boy]

Yes, I am looking for low to midrange torque. My question on the true duals should have been, how much will I lose by going with them?
If I bump the compression to 10.5 will I have trouble cranking it?
I was under the impression, it has 9:1 compression.

[prodrag1320]

even if not wanting to do headwork,just add a set of springs & go .590,then the cam will be there when you do decide to do headwork (IMO,ide do it now while its apart)

[HD Street Performance]

This is what I mean
Misinformation on the true compression this motor carries.
Not 9:1 regardless of factory rating.
The chambers are 98cc nominal.
True compression 8.5:1 when the piston crevices and a deck height (a swag) of .006 is used with the stock .045 gasket.
The torque is hit by all the factors.
The pipe is a large part of that, not the peak torque number as much but the shape of the torque curve. I have no way of knowing exact numbers just know the difference in bikes I have ridden and the feel stop light to the next, and passing when not above 3000 rpm in a gear,  noticeable.
The springs work at .590 no changes. The heads are the same as the old SE performance heads with 1.9 and 1.625 valves but have a huge hemi chamber instead of the 78cc bathtub
 

[txbear55]

How about a Redshift 557 cam and D&D Fatcat.  Designed specifically for the 103 CVO.  As those who build these things for a living (which is definitely not me!) recommend, you need a coordinated package for best results. Otherwise you waste money by trying to do it piecemeal and get less than stellar results.  Sometimes best to hold off until you can cut the big check and do it all.

[HD Street Performance]

Ok now you have a low compression 103 with a new cam. The other issues are  ot addressed. Any cam under 240 deg duration is an improvement for this motor but the early chain tensioners are an issue that needs to be addressed at the same time, in my opinion.

[Farm boy]

Understood,  that is why I was asking about the gear drive cams. The bike just turned 9700 miles. Planning on doing the 10k service this winter. Would like to do the cams as well. That was the reason for the original questions.
Thank you all for your input.

[Unbalanced]

How about a Redshift 557 cam and D&D Fatcat.  Designed specifically for the 103 CVO.  As those who build these things for a living (which is definitely not me!) recommend, you need a coordinated package for best results. Otherwise you waste money by trying to do it piecemeal and get less than stellar results.  Sometimes best to hold off until you can cut the big check and do it all.

The 5 sets of heads that I owned and had done were 94 or 95 cc.   2 of the builds started with the Zippers 575 gear drives.   You have to check the crank run out if your at .002 or greater then I would not go this route unless your going to fix the crank.   .003 was the spec to replace the crank back in the day unlike the .013 they claim today.   575 has great power down low with no headwork... If you did headwork you might consider the 570 S&S set compression to 10.1.   Those heads had 630 springs in them you shouldn't be concerned with spring with the cams your looking at expect for seat and open pressures.   a 50/51mm throttle body with the 4.35 injectors you have will also help out (you have a 43mm if stock).   I would not go bigger than 53mm though.   You can deck the heads and a max seems to be about .060 before you run into issues if you need more compression.  Can also put in 1.940 intakes   Have to always check piston to valve and valve to valve though just cant say he did so it must be ok.   Depending on which year ECM 03,04,05 you have some of them were able to run compression releases believe it was the 05 which meant you could drill the heads and not have to use manual compression releases.   

Good luck on the upgrades.

[rigidthumper]

A less expensive alternative to gear drives would be to convert to the hydraulic cam plate and tensioners from an 07 and newer TC, and a set of conversion cams ( made for the early cases on the inside, made for the late hydro setup on the outside). Here is a list of all the things you'd need to do this- http://mastertune.net/products_camshafts.html#footnote_1
TTS100 ( part number 2000302) would be my choice- much more early torque than the SE253s.